Governor-valve for hydraulic forcing-machines



(No Model.)

W. BURNHAM. GOVERNOR VALVE FOR HYDRAULIC PORGING MACHINES.

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UNITED STATES PATENT OFFICE.

IVALTER BURNHAM, OF HYDE PARK, ILLINOIS, ASSIGNOR TO CHARLES T. ROOT, O-F SHORT HILLS, NEIV JERSEY.

GOVERNOR-VALVE FOR HYDRAULIC FQRGING-IVIACHINES.

SPECIFICATION forming part of Letters Patent No. 452,360, dated May 19, 1891. Application filed January 26, 1889. Serial No. 297,699. (No model.)

' To all whom it may concern.-

Be it known that I, WALTER BURNHAM, of Hyde Park, Illinois, have invented certain Improvements in Governor-Valves for HydraulicForging-Machines, of which the following 1s a specification.

The object of this invention is to render the method of hydraulic forging more widely available in shaping and forging bodies of hot metal by greatly diminishing or practicallyeliminating the time ordinarily occupied in raising the operating-fluid in the hydraulic cylinder to the required high pressure after themovement of the ram through that part of its working stroke, which occurs before the body of hot metal has acquired contact with both of the forging or shaping dies. For conven ence the portion of the working stroke preceding the occurrence of such contact is called the contact-stroke. The remainder of the working stroke, during which the body of hot metal, hereinafter called the work, should be made to fill out the space between the d1es and take its finished shape therefrom, is designated the forging stroke.

The broad feature of the invention consists in the combination of the port through which theoperating-fluid is introduced into the ramcylinder with a yielding throttle-valve so loaded or adjusted by means of a weight, sprlng, or brake that the internal pressure required to move it from its throttling position and enlarge the area of the said port excoeds to a prescribed extent the pressure requlred to actuate the ram during its contactstroke; but when the ram encounters the resistance resulting from the contact of the work with both dies the pressure of the operat1ng-fluid in the ram-cylinder rises and the resulting back-pressure upon the end of the throttle-valve instantly forces it back and fully opens the port, and thus freely admits the operating-fluid at high pressure to effect the forging stroke. It follows that by the in tial constriction of the said port the operat- 1ng-fiuid in the accumulator or other source of supply is held back and maintained at the required high pressure during the whole of the contact-stroke, and is thus immediately available at the instant when the throttle- ValVe automatically opens the port wide at the commencement of the forging stroke. Hence the forging stroke is delivered with ample energy and with such rapidity that the forging operation is completed before the work has time to be too greatly chilled by its contact with the dies.

It will be seen that the val ve may be so adjusted as to more or less constrict the port through which the operating-fluid is supplied to the ram-cylinder and that it may have applied to it a weight, spring, or brake which will oppose more or less resistance to its opening movement, and that whatever may be the conditions of its adjustmentits operation during the working stroke of the ram is automatic. It is therefore designated a governor-valve for hydraulic forging-machines.

In the accompanying drawings, illustrating the invention, the governor-valve is in the form of a piston and has applied to it a spring for, if need be, assisting in holding it in its throttling position.

The drawings are as follows: Figure 1 is a sectional longitudinal section of the valveshell, showing the piston in elevation and in the throttling position which it may occupy during the contact-stroke. Fig. Zis a similar section showing the piston in the position which it is forced to acquire during the working stroke.

The valve-shell A has formed in it the chamber a, the side of which is provided with the hollow arm a for connection with the main pipe, which supplies high-pressu re fluid from an accumulator or other source. The port a is for conducting the high-pressure fluid from the valve-chamber a to the ram-cylinder. The throttle-valve consists of the endwise-sliding piston B, which has a suitablypacked bearing a in the hollow end A of the valve-sh ell, and upon its inn er end is provided with a projecting spider B, which by fitting within the port a aids in centralizing the piston.

A nut 0, provided upon its periphery with a male screw-thread, is adapted to engage and fit tightlyafemale sorewihread formed upon the interior surface of the outer portion of the hollow end A of the valve-shell. The nutO is centrally perforated to allow of the extension through it of the valve-stem B which near its outer end is screw-threadtjwl and provided with two jam-nuts (I l). A spring I), exerting an inward thrust upon the valvestem, tends to drive the piston toward the mouth a of the port a The nut b is a stop, which by collision with the end of the valveshell arrests the inward movement of the pis' ton. By adjusting the positions of the jamnuts the piston may he thus arrested with its end 13 at such distance from the mouth ct of the port (t as will leave the required relatively small opening for the supply of fluid to the rain-cylinder during the contact-stroke. The nut 0 serves as an abutment which fixes the limitof backward motion of thepiston induced by the increased back-pressure upon its end B during the forging stroke.

A check E, which during the contact-stroke bears upon the peripheryof the jam-nut l), as shown in Fig. 1, during the forging stroke springs into the space between the jam-nut b and the end of the valve-shell, as shown in Fig. 2, ing thrust inward by its spring D when the supply of high-pressure fluid is shut off at the conclusion of the forging stroke and during the withdrawal of the fluid from the ramcylinder while the ram is making its returnstroke, after which the check is withdrawn and the spring D forces the piston back to its throttling position preparatory to a repetition of the working stroke.

The friction upon the valve-piston of its packed seat will usually sufiiee to maintain the valve in its constricting position during the first portion of the working stroke of the rannwhich is herein designated the contactstroke. Thus the tight packing, acting as an eflicient brake, may serve as an equivalent for the spring D, and the spring D may be dispensed with, in which case after the conclusion of the working stroke and the emptyand thus prevents the piston from being of the ram-cylinder the valveepisto n may be pushed into its constricting position by power exerted manually.

\Vhat is claimed as the invention 1s 1. A governor-valve for a hydraulic forgingmachine for automatically enlarging the area of the port which supplies high-pressure fluid to the ram-cylinder during the latter portion of or what is herein called the forging stroke of the ram, the same consisting of a valve-chamber adapted for connection with the hi gh-pressure-tluid-supply pipe, a port for conducting the high-pressu re fluid from said valvechamber to the ram-cylinder, a valve yielding to internal pressure and adapted for throttling said port during the first portion of or what is herein called the contact stroke of the ram, and means for opposinga prescribed degree of resistance to the yieldlng movement of said valve, by which movement the area of said port is enlarged.

2. The combination, as herein set forth, ol"; the inlet-port of a hydraulic-ram cylinder wlth a valve for throttling said port adapted to yield and enlarge the area of said port when subjected to prescribed internal pressure, an adjustable stop for limiting the extent to which said valve can constrict the said port, and means,such as a spring, for holding said valve against said stop with a prescribed degree of force.

3. The combination, as herein set forth, of the valve-chamber a, the hollow arm a, the port (t the spring D, and the throttle-valve B with a chock E for automatically chocking the valve 13 when it is driven back by the preponderance over the force of its spring of the internal pressure exerted upon its end 13".

WALTER BURNHAM'.

\Vitnesses:

EDYVARD E. MORRILL, N. U. llESTON. 

